纹理在Qt中缩放而不是重复

我刚开始在qt中使用opengl,使用纹理我在quard中显示图像.

然后我将gltexture包装模式设置为gl_repeat但不重复.

我甚至试过gl_clamp_to_edge仍然无法正常工作.

图像大小256*256

码:

GLuint _textureId; //The id of the texture
int _wdth;
int _hight;
void LoadGLTextures( const char * name )
{
    QImage img;

    if(!img.load(name)){
        qDebug() << "ERROR in loading image";
    }

    QImage t = QGLWidget::convertToGLFormat(img);

    _wdth = t.width();
    _hight = t.height();
    qDebug()<<"width = "<<_wdth<<"height ="<<_hight;
    glGenTextures(1, &_textureId);
    glBindTexture(GL_TEXTURE_2D, _textureId);
    glTexImage2D(GL_TEXTURE_2D, 0, 3, t.width(), t.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, t.bits());

    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
}

void GLWin::initializeGL()
{
    qglColor(Qt::black);
    glEnable(GL_CULL_FACE);
    glShadeModel(GL_SMOOTH);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_MULTISAMPLE);
    static GLfloat lightPosition[4] = { 0.5, 5.0, 7.0, 1.0 };
    glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);
    ///cameraPos = 0;
    glEnable(GL_TEXTURE_2D);
    LoadGLTextures("resources/Green_Dragon.jpeg");
}
void GLWin::paintGL()
{
       glClearColor( 0.0f, 0.0f, 0.0f, 0.0f);
       glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );

       glMatrixMode( GL_MODELVIEW );
       glLoadIdentity();

       glEnable(GL_TEXTURE_2D);
       glColor3f(0.5, 0.5, 0);
       glBindTexture(GL_TEXTURE_2D, _textureId);

       glBegin(GL_QUADS);
       glTexCoord2f(0.0f, 0.0f); glVertex2f(-0.5f, -0.5f);  // vertex 1
       glTexCoord2f(1.0f, 0.0f); glVertex2f(0.5f, -0.5f); // vertex 2
       glTexCoord2f(1.0f, 1.0f); glVertex2f(0.5f, 0.5f); // vertex 3
       glTexCoord2f(0.0f, 1.0f); glVertex2f(-0.5f, 0.5f); // vertex 4
       glEnd();
       glDisable(GL_TEXTURE_2D);
       glFlush();
}
void GLWin::resizeGL(int width, int height)
{
    glViewport(0, 0, (GLint)width, (GLint)height);
    glMatrixMode(GL_PROJECTION);  // To operate on the Projection matrix
    glLoadIdentity();
    glOrtho(-0.5, 0.5, -0.5, 0.5, -1, 1);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

Nicol Bolas.. 6

   glTexCoord2f(0.0f, 0.0f); glVertex2f(-0.5f, -0.5f);  // vertex 1
   glTexCoord2f(1.0f, 0.0f); glVertex2f(0.5f, -0.5f); // vertex 2
   glTexCoord2f(1.0f, 1.0f); glVertex2f(0.5f, 0.5f); // vertex 3
   glTexCoord2f(0.0f, 1.0f); glVertex2f(-0.5f, 0.5f); // vertex 4

如果这些是你的纹理坐标,那么它不打算重复.纹理包裹模式仅在纹理坐标超过[0,1]范围时应用.由于纹理坐标在该范围内,因此不会发生重复.

您可以看到纹理缩放,因为您正在缩放三角形的位置.因此,纹理将根据那些缩放位置进行映射.

如果要缩放纹理坐标,可以使用纹理矩阵对纹理坐标进行一些变换.

   glTexCoord2f(0.0f, 0.0f); glVertex2f(-0.5f, -0.5f);  // vertex 1
   glTexCoord2f(1.0f, 0.0f); glVertex2f(0.5f, -0.5f); // vertex 2
   glTexCoord2f(1.0f, 1.0f); glVertex2f(0.5f, 0.5f); // vertex 3
   glTexCoord2f(0.0f, 1.0f); glVertex2f(-0.5f, 0.5f); // vertex 4

如果这些是你的纹理坐标,那么它不打算重复.纹理包裹模式仅在纹理坐标超过[0,1]范围时应用.由于纹理坐标在该范围内,因此不会发生重复.

您可以看到纹理缩放,因为您正在缩放三角形的位置.因此,纹理将根据那些缩放位置进行映射.

如果要缩放纹理坐标,可以使用纹理矩阵对纹理坐标进行一些变换.